1. Field of the Invention (Technical Field)
The present invention relates to a specialized drape for use on surgical instrument tables or carts in hospital operating rooms, particularly to a sterile drape for use on a two-tiered instrument cart.
2. Background Art
During most medical surgeries, the surgeon must have convenient access to numerous surgical instruments. Often, the instruments are disposed upon a sterilized wheeled cart (or sometimes a wheelless table) situated in the operating room, near the operating room table. The cart has one or more shelves upon which the surgical instruments are placed for ready access.
In complex surgeries, so many instruments may be required that more than one shelf are required to hold all the instruments for ready use. Accordingly, presently in the art, more than one cart may be used, which crowds the operating room and complicates efforts to maintain the sterility of the operating area. Alternatively, operating room personnel may place instruments upon more than one tray, and then stack the trays one upon another on a single cart, which unfortunately complicates access to the instruments. Un-stacking and re-stacking trays of instruments upon a single cart takes too much time and increases the possibility of mishaps. Still, there is a need for rapid and ready access to all the instruments, without needlessly cramping the work area in the operating room with multiple cartsxe2x80x94especially in smaller operating rooms.
In order to promote the ready accessibility of surgical instruments and tools during an operation, multi-tier instrument carts are frequently used in operating rooms. Increasingly popular for their versatility, multi-tier instrument carts and tables typically feature a main table-top surface and a smaller auxiliary shelf disposed parallel to and above the main surface. The main and auxiliary surfaces are mounted upon a frame that typically is wheeled for convenient movement about the hospital. The wheels often are lockable against rotation to secure the cart when in use. The main table surface provides a generously sized surface area to hold instruments at a convenient hip or waist-high level. These two-tier carts, sometimes called xe2x80x9cback instrument tables,xe2x80x9d feature one auxiliary shelf having a top surface area somewhat less in size than the top surface area of the main surface; conventionally, the auxiliary shelf has the same length (right-to-left) as the main surface, but is considerably narrower in front-to-back dimension. The shelf is spaced above the main surface, and is situated rearward on the cart in relation to the main surface, so that the auxiliary shelf overhangs the back approximately one-third to one-half of the main surface. A suitable multi-tier operating room cart is described in detail in U.S. Pat. No. 6,189,459 to DeAngelis, all the teachings of which are incorporated herein by reference.
Another challenge in surgical operating rooms is the preservation of the sterile field. It is important to provide a sterile field that includes all auxiliary tables and carts upon which surgical instruments are arrayed for access by operating room personnel. It is known, for example, to provide covers for hospital gurneys and tables, such as the cover shown in U.S. Pat. No. 5,436,053 to Herum, and to provide some means for securing a cover to a table, such as that disclosed in U.S. Pat. No. 4,627,363 to Jones.
The popularity of two-tier operating room carts, coupled with the demand that the instrument surfaces of such carts be sterile, has presented some challenges. Operating room personnel appreciate the order and convenience offered by dual-tier instrument carts, but assuring that the two instrument surfaces are sterile before the placement of tools thereon has proven problematic. Sterility of instrument cart surfaces sometimes is provided by placing a sterile drape upon each of the cart""s instrument surfaces. Placement of sterile drapes on two-tier carts, however, is complicated by the duel-surface configuration. For example, it is extremely preferable to cover not only the horizontal surfaces upon which the instruments will be situated, but also to provide a sterile barrier in front of the frame members supporting the auxiliary shelf. Thus, in order to maintain the integrity of the overall sterile field, some sort of vertically situated panel preferably is provided to extend down from the upper auxiliary shelf to the main table surface, so that a sterile shield is disposed between the main table surface and the frame components that support the upper auxiliary shelf. One effort to meet the challenge is simply to provide two drapes; a bottom section to cover the main instrument surface, and a top section for covering the upper auxiliary shelf surface. The top section then may be provided with a middle or curtain portion that hangs down to come into contact with the bottom section. This type of two-section drape is suggested in U.S. Pat. No. 6,189,459 to DeAngelis, currently co-owned by the applicant. Another two-piece type of drape is described in U.S. Pat. No. 6,019,102 to Becker.
Two-section drapes suffer from a number of drawbacks, most of all their complexity and/or cost of manufacture. The ""102 patent to Becker, for example, teaches a two-section drape characterized as having either a xe2x80x9ctwo-piecexe2x80x9d or a xe2x80x9cone piecexe2x80x9d embodiment. Both the xe2x80x9cone-piecexe2x80x9d and the two-piece embodiments, however, are fashioned from multiple sections of drape material; Becker""s xe2x80x9cone-piecexe2x80x9d embodiment is substantially identical to his two-piece embodiment, except that a manufactured seam is provided along the line where the two pieces are permanently joined together. The seam is along an edge of a vertically hanging portion of the top section, where it is joined to the horizontal surface of the bottom section at the time of manufacture. (In the two-piece embodiment, the top section is allowed to hang down into abutting contact with the bottom section, without being affixed thereto.) Thus, the manufactured seam of the xe2x80x9cone-piecexe2x80x9d embodiment of the Becker device is a complicated, expensive juncture; an edge of the top section must be joined to a plain, broad surface of the bottom section, with the result that the seam joins mutually perpendicular sections when the drape is in use. Not only does such a seam significantly complicate the manufacturing method of the Becker device, but the seam is subjected to considerable stresses while the drape is being placed on the dual-tier cart and/or while the drape and cart are in use. If the seam fails, the edge of the top section may tear away from the working surface of the bottom section, which may compromise the sterile field.
Operating room personnel sometimes resort to merely arranging an array of sterilized towels upon cart shelves to provide a sterile, absorbent working surface. Towels suffer from the need to be laundered and sterilized for later re-use, and also have no impermeable layer to prevent fluids from undesirably soaking through to the metal surfaces of the shelves.
A significant need remains for a simple, inexpensive, easy-to-use sterile drape for covering dual-tier operating room carts. Against the foregoing background, the present invention was developed.
There is provided according to the invention a special custom drape for placement upon a two-tier cart to provide a sterile covering for working surfaces of the cart, and a method for manufacturing the drape. The drape includes several special features which permit it to be handled, placed upon the auxiliary shelf, and secured in place with minimal challenges to sterility and to maintain the sterile field in the operating room.
According to the apparatus of the invention a drape is provided for use in covering a two-tier medical cart, the cart having a main shelf, an auxiliary shelf, and vertical support members extending between the shelves, the drape comprising a seamless foundation substrate comprising a sheet of flexible, impermeable plastic having an upper absorbent portion, a medial portion, a lower absorbent portion, and a lower skirt portion; a first absorbent surface disposed upon the substrate to define the upper absorbent portion; and a second absorbent surface disposed upon the substrate separate from the first absorbent surface to define the lower absorbent portion, wherein the medial portion comprises a portion of the substrate uncovered by an absorbent surface, between the upper absorbent portion and the lower absorbent portion, and also wherein the lower skirt comprises a portion of the substrate uncovered by an absorbent surface, and the lower absorbent portion is between the skirt and the medial portion. The upper absorbent portion has side edges and is folded and adhered along the side edges to define an envelope for receiving the auxiliary shelf. The first absorbent surface and the second absorbent surface each comprises a permeable plastic matrix layer and an absorbent layer intermediate between the substrate and the matrix layer, the matrix and absorbent layers pressed parallel together and adhered to the substrate. The drape preferably also features flexible side flaps extending from the medial layer, the side flaps being wrappable around the cart""s vertical support members. The preferred embodiment of the drape apparatus has at least two flexible pull tabs, extending from the upper absorbent portion, for allowing the drape to be manipulated without handling the upper absorbent portion, the medial portion, the lower absorbent portion, and the lower skirt portion. The pull tabs preferably are two pairs of pull tabs, a pair extending from opposite sides of the upper absorbing portion, and each tab ideally has a lateral perforation permitting each the tab to be torn along the perforation for detachment from the upper absorbent portion. The drape also has at least one adhesive fastener disposed upon the first absorbent surface on the upper absorbent portion, wherein when the drape is installed upon the cart, the medial portion may be drawn into adhesive contact with the at least one adhesive fastener to maintain the medial portion pulled away from the lower absorbent portion.
Objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.